The present invention relates to smoking articles such as cigarettes, and in particular to cigarettes which generate low amounts of visible sidestream smoke.
Popular smoking articles, such as cigarettes, have a substantially cylindrical rod shaped structure and include a charge of smokable material, such as shredded tobacco (e.g., cut filler), surrounded by a paper wrapper thereby forming a so-called "tobacco rod." It has become desirable to manufacture cigarettes having cylindrical filter elements aligned in an end-to-end relationship with the tobacco rod. Typically, filter elements are manufactured from fibrous materials such as cellulose acetate and plug wrap, and are attached to the tobacco rod using a circumscribing tipping material. It also has become desirable to perforate the tipping material and plug wrap, in order to provide for dilution of drawn mainstream smoke with ambient air.
Cigarettes are employed by the smoker by burning one end thereof. The smoker then receives mainstream smoke into his/her mouth by drawing on the opposite end (e.g., the filter end) of the cigarette. During the time that the cigarette is not being drawn upon by the smoker, it remains burning, and sidestream smoke is generated. Sidestream smoke is smoke which directly enters the atmosphere during the static burn period of a cigarette. Sidestream smoke diffuses into the atmosphere, and the characteristic visible nature thereof may be perceived negatively by certain individuals. Thus, certain cigarette smokers have indicated a desire to decrease the levels of visible sidestream smoke generated by their cigarettes.
Cigarette paper wrappers for the preparation of tobacco rods are set forth in U.S. Pat. No. 4,231,377 to Cline et al, U.S. Pat. No. 4,420,002 to Cline, U.S. Pat. No. 4,461,311 to Mathews et al, U.S. Pat. No. 4,450,847 to Owens, U.S. Pat. No. 4,805,644 to Hampl, Jr. et al, U.S. Pat. No. 4,881,557 to Martin and U.S. Pat. No. 4,915,118 to Kaufman et al. The paper wrappers proposed in the foregoing patents have a propensity to provide cigarettes which generate relatively low levels of visible sidestream smoke. A cigarette which generates relatively low levels of visible sidestream smoke is set forth in U.S. Pat. No. 4,924,888 to Perfetti et al. However, cigarette paper wrappers which are useful for manufacturing cigarettes which generate low amounts of visible sidestream smoke upon use, particularly those wrappers which include magnesium hydroxide as a filler component, often have the propensity to provide, upon use, an ash having flaky properties.
It would be desirable to provide a cigarette which incorporates a paper wrapper such that upon use (i) the cigarette generates low levels of sidestream "tar" and hence low levels of visible sidestream smoke, (ii) the cigarette provides good flavor and smoking satisfaction to the smoker thereof, (iii) the ash of the paper wrapper is fairly cohesive and not highly flaky, and (iv) is capable of sustaining smolder at least under FTC smoking conditions.